背景
最近让我做一个大数据的系统，分析了一下，麻烦的地方就是多数据源切换抽取数据。考虑到可以跨服务器跨数据库抽数，再整理数据，就配置了这个动态数据源的解决方案。在此分享给大家。
实现方案
数据库配置文件
我们项目使用的是yml形式的配置文件，采用的是hikari的数据库连接池。第一步我们自然是配置多个数据库源头。
我们找到spring的datasource，在下方配置三个数据源。
spring:
application:
name: dynamicDatasource
datasource:
test1:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/test1?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false
username: root
password: 123456
test2:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/test2?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false
username: root
password: 123456
test3:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/test3?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false
username: root
password: 123456
hikari:
leak-detection-threshold: 2000定义数据源实体类
我们可以建立个datasourceBean文件夹专门管理数据源的实体类。
我们这里要建立三个实体类。分别对应test1，test2，test3
@Configuration
public class Test1DataSourceBean {
@Value("${spring.datasource.test1.driver-class-name}")
private String test1Driver;
@Value("${spring.datasource.test1.url}")
private String test1Url;
@Value("${spring.datasource.test1.username}")
private String test1Username;
@Value("${spring.datasource.test1.password}")
private String test1Password;
@Bean(name="test1DataSource")
public DataSource test1DataSource() throws Exception{
HikariDataSource dataSource = new HikariDataSource();
dataSource.setDriverClassName(test1Driver);
dataSource.setJdbcUrl(test1Url);
dataSource.setUsername(test1Username);
dataSource.setPassword(test1Password);
return dataSource;
}
}@Configuration
public class Test2DataSourceBean {
@Value("${spring.datasource.test2.driver-class-name}")
private String test2Driver;
@Value("${spring.datasource.test2.url}")
private String test2Url;
@Value("${spring.datasource.test2.username}")
private String test2Username;
@Value("${spring.datasource.test2.password}")
private String test2Password;
@Bean(name="test2DataSource")
public DataSource test2DataSource() throws Exception{
HikariDataSource dataSource = new HikariDataSource();
dataSource.setDriverClassName(test2Driver);
dataSource.setJdbcUrl(test2Url);
dataSource.setUsername(test2Username);
dataSource.setPassword(test2Password);
return dataSource;
}
}@Configuration
public class Test3DataSourceBean {
@Value("${spring.datasource.test3.driver-class-name}")
private String test3Driver;
@Value("${spring.datasource.test3.url}")
private String test3Url;
@Value("${spring.datasource.test3.username}")
private String test3Username;
@Value("${spring.datasource.test3.password}")
private String test3Password;
@Bean(name="test3DataSource")
public DataSource test3DataSource() throws Exception{
HikariDataSource dataSource = new HikariDataSource();
dataSource.setDriverClassName(test3Driver);
dataSource.setJdbcUrl(test3Url);
dataSource.setUsername(test3Username);
dataSource.setPassword(test3Password);
return dataSource;
}
}定义一个枚举类管理数据源
public enum DatabaseType {
test1("test1", "test1"),
test2("test2", "test2"),
test3("test3","test3");
private String name;
private String value;
DatabaseType(String name, String value){
this.name = name;
this.value = value;
}
public String getName(){
return name;
}
public String getValue(){
return value;
}
}定义一个线程安全的数据源容器
public class DatabaseContextHolder {
private static final ThreadLocal<DatabaseType> contextHolder = new ThreadLocal<>();
public static void setDatabaseType(DatabaseType type){
contextHolder.set(type);
}
public static DatabaseType getDatabaseType(){
return contextHolder.get();
}
}定义动态数据源
public class DynamicDataSource extends AbstractRoutingDataSource{
protected Object determineCurrentLookupKey() {
return DatabaseContextHolder.getDatabaseType();
}
}
#### mybatis配置类
网上的很多文章配置出来都会产生数据源循环依赖的问题，这里解决了这个问题。@Configuration
@MapperScan(basePackages="cn.test.jichi", sqlSessionFactoryRef="sessionFactory")
public class MybatisConfig {
/**
* @Description:设置动态数据源
*/
@Bean(name="dynamicDataSource")
@Primary
public DynamicDataSource DataSource(
@Qualifier("test1DataSource") DataSource test1DataSource,
@Qualifier("test2DataSource") DataSource test2DataSource,
@Qualifier("test3DataSource") DataSource test3DataSource){
Map<Object, Object> targetDataSource = new HashMap<>();
targetDataSource.put(DatabaseType.test1, test1DataSource);
targetDataSource.put(DatabaseType.test2, test2DataSource);
targetDataSource.put(DatabaseType.test3, test3DataSource);
DynamicDataSource dataSource = new DynamicDataSource();
dataSource.setTargetDataSources(targetDataSource);
dataSource.setDefaultTargetDataSource(test1DataSource);
return dataSource;
}
/**
* @Description:根据动态数据源创建sessionFactory
*/
@Bean(name="sessionFactory")
public SqlSessionFactory sessionFactory(
@Qualifier("test1DataSource") DataSource test1DataSource,
@Qualifier("test2DataSource") DataSource test2DataSource,
@Qualifier("test3DataSource") DataSource test3DataSource) throws Exception{
SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
//构造方法，解决动态数据源循环依赖问题。
sessionFactoryBean.setDataSource(this.DataSource(test1DataSource,test2DataSource, test3DataSource));
return sessionFactoryBean.getObject();
}}
#### 提供一个示例public void testDymnaicDatasource(){
//不切换数据源默认是自己的。
System.out.println("-----默认数据源");
DemoEntity totalCount = demoMapper.getTotalCount();
String nameCount1 = totalCount.getNameCount();
String ageCount2 = totalCount.getAgeCount();
System.out.println("nameCount:"+nameCount1);
System.out.println("ageCount:"+ageCount2);
//数据源切换为branch
System.out.println("-----数据源为test2");
DynamicDataSourceUtils.chooseBranchDataSource();
Integer nameCount = demoMapper.getNameCount();
Integer ageCount = demoMapper.getAgeCount();
System.out.println("nameCount:"+nameCount);
System.out.println("ageCount:"+ageCount);
//数据源为basic
System.out.println("-----数据源为test3");
DynamicDataSourceUtils.chooseBasicDataSource();
Integer ageCount1 = demoMapper.getAgeCount();
System.out.println("ageCount:"+ageCount1);
}```
总结
至此实现了多数据源的动态切换。可以在同一个方法里面进行操作多个数据源。
